The goal of the Tissue Culture Shared Service is to enhance the quality of laboratory research at the Arizona Cancer Center by providing specialized cell culture services to Cancer Center investigators. The objectives of the service include providing: 1. Cell lines for addressing cancer-related research questions; 2. Cost-effective quality control measures necessary for excellent science with in vitro cancer models; 3. Reagents for cell culture that are not commercially available or are more cost-effective when obtained through the service; 4. Consultative expertise in tissue culture; 5. Assistance to the genetically modified nice shared service in establishing knock-mice. More than 250 human tumor-derived cell lines have been established by the Tissue Culture Shared Service. Cancer Center investigators have used these in cytogenetic and molecular studies to identify genetic changes in cancer and in pharmacological studies to evaluate new chemotherapeutic agents. Cell lines from this bank also have been provided to the NCI and ATCC. This service provides cost effect mycoplasma screening of cell lines to encourage regular testing. This helps ensure that results obtained by Center investigators using in vitro models are not artifacts of mycoplasma infection. The service conducts quality assurance/quality control testing of fetal bovine serum lots. The effectiveness of different lots at supporting cell line growth relative to cost is assessed and large lot prices are then negotiated at a considerable savings to investigators. By maintaining embryonic stem cell culture for the Genetically Modified Mice Shared Service, it is anticipated that the expertise of the personnel in the Tissue Culture Shared Service will be key to the successful development of knock-out mouse models at the Arizona Cancer Center.